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Test for Semiconductor Contact Hole Opening

IP.com Disclosure Number: IPCOM000079773D
Original Publication Date: 1973-Sep-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Barson, F: AUTHOR

Abstract

Slight residual SiO(2)in contact holes in an overlying SiO(2) layer on a semiconductor body is difficult to detect visually. The presence of Slight residual SiO(2) in contact holes in an overlying SiO(2) layer on a semiconductor body is difficult to detect visually. The presence of residual SiO(2) interferes with the process of making good contact with the semiconductor by the metal land of the interconnection system.

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Test for Semiconductor Contact Hole Opening

Slight residual SiO(2)in contact holes in an overlying SiO(2) layer on a semiconductor body is difficult to detect visually.

The presence of Slight residual SiO(2) in contact holes in an overlying SiO(2) layer on a semiconductor body is difficult to detect visually. The presence of residual SiO(2) interferes with the process of making good contact with the semiconductor by the metal land of the interconnection system.

In this method, the substrate covered by a layer of insulating material containing contact openings is exposed to a solution of AgNO(3) in HNO(3) and HF, with a dilution of HF sufficiently low to avoid attacking the insulating layer. This solution provides a suitable indicator of an open contact hole. The silver in the solution plates out on a silicon surface but not on a SiO(2) surface.

The plated silver can be visually detected and provides an indication of complete contact hole openings. The silver can then be removed chemically after the test, without fear that a slight trace remaining will cause junction poisoning.

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